The present invention relates to an ultrasonic vibrator and an ultrasonic treatment device which excite ultrasonic waves.
Piezoelectric elements that use a piezoelectric effect for driving have been conventionally used in various applications such as an ultrasonic vibrator. The resonant frequency of such a piezoelectric element changes with slight variations in dimension etc. Adjustments need to be made to obtain a desired value.
For example, a technique has been disclosed in which driving electrodes to which a voltage is applied are arranged over an entire plane lying in a driving direction of a piezoelectric element, and some adjustment electrodes among the driving electrodes are electrically disconnected to adjust the resonant frequency (see JP 2006-254683 A).